Sensors and buttons

A sensor is how the yard knows someone is there. Anything that switches a wire on or off will work.

Sensor	Good for	Notes
PIR motion (HC-SR501, AM312)	“someone walked up”	needs about a minute to settle after power-up. The knobs on an HC-SR501 set its range and how long it stays on.
Pressure mat	“someone stepped here”	a switch: wire it like a button
Break-beam (IR or laser)	“someone crossed the path”	precise and fast, good for a hallway
Button	a manual “go”	wire it between a pin and GND

Wiring

Sensors with their own output (PIR, beam receivers): wire power, ground, and their OUT to a board pin. In the console set pull to none, because the sensor drives the pin itself.

Switches (buttons, pressure mats, reed switches): one wire to the pin, the other to GND. Set pull to up and tick active = LOW. The pin then reads “on” when the switch connects it to ground.

Which pin?

Some pins can only be inputs. On the DevKit V1 those are VP, VN, D34 and D35. Use them for sensors and keep the other pins free for outputs. Those four have no internal pull-up, though, so a button on one of them needs an extra resistor. Put buttons on a pin that has a pull-up instead. The board pages list which pins are which.

In the console

Assign the pin to Sensor / button input, set pull and active = LOW as above, and Save to node. The TEST column shows ● ACTIVE or ○ clear live. Walk past, step on the mat or press the button and watch it change.

Then make it do something: see Triggers.

On a battery board

A battery prop sleeps when the show is off, and only some pins can wake it. Put its sensor on one of those. The console warns you if you don’t. See Battery props.